PM Research #7 It Begins

[Janderso]

That sounds like a good idea

 

[ErichKeane]

When I made my #5 I centered the cylinder bore using the outside of the casting.

Yep, I did the same! I used my coax indicator on the 3 sides. It is still a casting, so the best you can do is a few thou, but it is at least it is a nicer casting than the inside.

EDIT: I also did this with a boring bar on my mill instead of my lathe, since I wanted to make sure the head bolts were done in the same operation.

 

[Janderso]

I used my coax indicator on the 3 sides

I hope you didn't turn it on. Good idea.

 

[Lo-Fi]

As interesting references, Blondihacks has a series building a No. 1. Kudos to Quinn for showing stuff that didn't go as well as she hoped, as is so often the case for us hobbyists. Joe Pie has chimed in with alternative methods for some of the "how the hell do I do that?!" setups such as referencing the piston rod bore against the slide bars from the outside, and subsequently how to pick up the crank location into the rough casting from the same references on an angle. Seen him accused of mansplaining (actually on here), but don't honestly believe it's anything other than seeing less than optimal methods (I spent days puzzling how to do it better myself - it's tricky!) and having the experience to share for a better way. I facepalmed so hard at how cunning his latest on picking up the crank bores is.
Looking forward to following your build

 

[Janderso]

Lo-fi,
I watched both of the referenced videos.
I didn’t understand what Joe-Pi was up to as I watched his rendition first.
Then I considered his motive. Hopefully it is as you say.
Being new to the model game, being a novice machinist, the irregular castings can be very challenging to set up, verify and machine without the bozo affect.
The castings are also hard to clamp. Thin cast iron is a tricky business.
I think I will go back and watch Joe’s video again. He is one smart Texan.
Cheers

 

[Lo-Fi]

Just had a nose right through your album. Some lovely setup and measuring/marking work right there!

 

[Janderso]

Just had a nose right through your album. Some lovely setup and measuring/marking work right there!

Thank you Lo-Fi, I hope I get good results when I go to assemble the components.
I won't have time to get back on it for a week or so. I am looking forward to trying again on the two new cylinders (one not done yet and one coming to replace the bad part I made)
I'm learning a bunch. Fiddly work.
I'm shaming Joe-Pi on Youtube to do a video on steam engine cylinders. He has done two recently on the set up of Blondi-Hacks.
His latest

 

[Janderso]

Need help!
I really don’t want to screw up another cylinder.
I have the cylinder centered in the four jaw as shown.
Is there a better way?
The cylinder at 90- 180 and 270 degrees is centered this way.
Thanks

 

[ErichKeane]

That seems like a perfectly fine way to do it. Just make sure you don't use a drill-bit, use a boring bar there, otherwise the bit will be drilling off center and will drift (or worse, catch and remove the part from the chuck)!

Is the back of the cylinder 'flat'? You likely want to make sure that is the case so you can square up both sides at the same time (unless you're going to flatten the other side on the mill).

 

[EricB]

I would make sure that the end of the cylinder that mates to the frame is facing out (the inboard head mating surface, 3 bolt holes). When you bore the cylinder you can also face that end at the same time and the cylinder bore will be true when it's installed.

Since you have a twin engine your two cylinders will be opposites so keep track of which is goes where.

Eric